I've been asked a few time for the code that performs localization. So here it is. This code does the modulation of the laser, scans the platform over approx 180 degrees, performs peak detection looking for 3 beacons that are at known locations. Having identified the beacons it uses the obtained angles to calculate the pose. The code is not pretty, I put it together very quickly to test things out. Use it or ignore it as you see fit.

Even though I've posted my code I would encourage anyone trying to do this sort of localization to read the paper above. Try and work out your solution to implementing the algorithm. Playing around with the actual calculations and feeding in different examples of position and angles really gives you a feel for how it works.